Control of searching and tracking mechanisms



Dec. 6, 1960 w. E. NEWMAN ETAL 2,963,559

CONTROL OF SEARCHING AND TRACKING MECHANISMS Filed July 8. 1953 United States Patent O CONTROL OF SEARCHING AND TRACKING MECHANISMS William E. Newman, Moorestown, and Herbert Singer,

West Collingswood, N.J., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed July 8, 1953, Ser. No. 366,710

1 Claim. (Cl. 200-) The invention described herein may be manufactured by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to switching apparatus and particularly relates to a switching apparatus for use in connection with the tilting controls for a radar searching and tracking mechanism.

It has been found that when using a pair of multiposition switches to control the movements of the radar mechanism, there have been many occasions when these controls have crossed each other and resulted in damage to the mechanism. It is, therefore, one object of this invention to provide a means for preventing such crossing of the tilting controls.

Another object of this invention is to provide a positive mechanical interlock between two multiposition switches.

Another object of this invention is to provide a positive mechanical interlock between the switches wherein the interlock is simple of construction, having relatively few parts subject to maintenance problems, and yet being fully automatic.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

Fig. 1 is a rear elevational view of one embodiment of the invention with the rear panel deleted.

Fig. 2 is a side view of the invention illustrated in Fig. 1 taken on the line 22 of Fig. 1.

Fig. 3 is a rear elevational view of a second embodiment of the invention with the rear panel deleted.

Fig. 4 is a side view taken on line 4-4 of Fig. 3.

Fig. 5 is a detail view on line 55 of Fig. 3 showing the configuration of the stop projecting from the pulley.

Referring now in greater detail to the drawing wherein similar reference characters refer to similar parts, a frame generally designated as is provided for the switch means. The frame 10 consists of a front plate 12 and a rear plate 14. Fixed between the two plates of the frame is a top shaft 16 and a pair of parallel bottom shafts 18 and 20. Mounted on the shaft 16 are a pair of coaxial gears 22 and 24 while on the shaft 18 is mounted a gear 26 adapted to mesh with gear 22 and on shaft 20 is mounted a gear 28 adapted to mesh with gear 24. An actuating handle 30 is provided at the front end of the shaft 18 and another handle 32 is provided at the front end of shaft 20. A multiposition switch contact member is provided at the rear end of each of the shafts "ice ,4

18 and 20, one such contact member being shown at 34. A pin 36 extends from a predetermined position on the rear surface of the gear 22 and a corresponding pin 38 extends from the front surface of the gear 24. These two pins are positioned in overlapping arrangement with each other in a circular plane.

Either switch member 30 or 32 can be rotated independently as long as their respective positions do not overlap, the gear 26 driving the gear 22 and the gear 28 driving the gear 24. However, as soon as one of the switches gets into position to overlap the other, the pins 36 and 38 engage each other and make a positive connection linking the two switches through the gears. Thus, for example, if switches 30 and 32 are in the position shown in Figure 1 of the drawing and switch 30 is rotated in a clockwise direction from its second toward its third rotary position, gear 26 also rotates in a clockwise direction, gear 22 rotates in a counterclockwise direction, pin 36 on gear 22 engages pin 38 on gear 24, gear 24 rotates in a counterclockwise direction, gear 28 rotates in a clockwise direction, and switch 32 is actuated from its third to its fourth rotary position. Similarly if switch 32 is operated from its third toward its second rotary position, switch 30 is actuated due to the mechanical interconnection between gears 28, 24, 22 and 26 and pins 38 and 36 from its second toward its first rotary position. In this way simultaneous identical relative positions of switches 30 and 32 is prevented.

A second embodiment of the invention is illustrated in Figs. 3, 4 and 5. In this embodiment a pulley and cable system is substituted for the gearing of the first embodiment, this second system comprising a pair of pulleys 50 and 52 mounted on a frame generally designated 54 and consisting of front and rear panels respectively designated as 56 and 58. A pair of parallel shafts 60 and 62 extend between the plates to rotatably support pulleys 50 and 52 respectively. Handles 64 and 66 and switch contact members, one of which is shown at 68, are all similar to their corresponding parts in the first embodiment.

A flexible cable 70 extends over the two pulleys, the ends of this cable being fastened within a groove 72 in the pulley 50. A bead 74 is formed at one position on the cable and is adapted to coact with a stop 76 projecting from the pulley 52. The stop 76, as best shown in Fig. 5, is in the form of a forked finger having a bottom recess which is adapted to allow the cable to pass therethrough but which prevents the passage of the head 74. This stop 76 and head 74 coact in the same way as the pins in the first embodiment in that they form a linkage between the two pulleys to prevent overlap of the respective switch positions. Accordingly the cable 70 slides freely over the pulley 52 and through the projection or stop 76 until the bead 74 comes into contact with the stop 76. Since the head is so positioned on cable 70 that the bead and the stop come into contact only when switches 64 and 66 approach similar instantaneous positions, an overlapping condition of the switches is prevented.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claim the invention may be practiced otherwise than as specifically described.

What is claimed as the invention is:

A multiple switch device comprising a support; a pair of shafts rotatably mounted on said support; switch means operatively connected to each of said shafts; a pulley mounted on each of said shafts for rotation therewith; a cable which encircles the pulleys and which normally slides freely over the periphery of one of said pulleys, the cable being secured to the periphery of the other pulley; a projection which is secured to the periphery of said one pulley and through which the cable passes freely; and stop means which is secured to the cable and which engages the said projection when a predetermined relative position of the switches is reached.

References Cited in the file of this patent UNITED STATES PATENTS 

